This invention relates generally to tools useful in automotive maintenance and, more specifically, to an adjustable wrench for securely gripping and twisting an oil filter to tighten or loosen the filter when threaded onto a filter mount.
The importance of automobiles and other motorized vehicles in reliably and efficiently transporting people and goods has encouraged the growth of what has become a large service industry devoted to maintaining and repairing such vehicles. It is generally recognized that regular periodic maintenance for vehicles such as cars, trucks, buses and the like, is necessary to keep the engines of these vehicles running at peak efficiency and to minimize or prevent premature mechanical failures. The trend to reduce the size of many automobiles, and the regular inclusion of auxiliary components, such as air conditioning and smog control devices, within engine compartments has limited access to some of the engine components requiring regular maintenance and has required, in some instances, the use of special tools. For example, in many engine compartments the location and size of the oil filter has made it virtually impossible or impractical to either loosen or tighten the filter utilizing standard wrenches or clamps. Because of such problems, several tools have been developed which facilitate the emplacement or removal of the oil filter from an engine filter mount.
One of these tools is a levered wrench having generally a smooth flexible band attached to a levered handle which tightens the band about an oil filter as the handle is pulled through an arc around a portion of the oil filter. The movement of the handle through the arc causes, in theory, the band to frictionally engage and securely grip the outer surface of the oil filter. As extra force is applied to further move the handle through the arc about the oil filter, that force will be transferred through the wrench to apply a torque upon the filter for twisting it. Such levered wrenches have several drawbacks, however, in that the frictional engagement between the smooth flexible band and the underlying portion of the oil filter cannot always be relied upon to securely hold the filter within the wrench and prevent slipping as greater torque is applied. Also, due to the combined tightening and twisting action of the handle, these wrenches are inherently unidirectional after placement, and if incorrectly positioned they must be removed and repositioned for tightening or loosening of the filter as required. Further, many such wrenches can accommodate only a rather narrow size range of oil filters due to the leveraging action of the handle, and the placement of oil filters in some engine compartments makes use of such wrenches impractical because the area through which the levered handle can be pulled is less than that area required to simply tighten the band about the filter.
Another tool for emplacing or removing an oil filter from an engine filter mount includes an enlarged socket which can be placed over the end of the oil filter to engage a series of flat surfaces typically surrounding and adjacent the outwardly extending end of the filter. A ratchet-type wrench can be connected to this enlarged socket to twist the oil filter as desired. As in the case of the levered wrenches, such enlarged socket wrenches also have several drawbacks which have limited their use and widespread acceptance. For instance, because there are many different types and brands of oil filters available, a mechanic servicing different makes and models of vehicles may find it necessary to purchase several of the enlarged sockets to accommodate the various sizes of filters encountered. Moreover, such enlarged socket wrenches are reliant upon the provision of a plurality of flat surfaces adjacent the outwardly extending end of the oil filter for gripping the oil filter. If these flat surfaces are not provided, or if they have been malformed or damaged, the enlarged socket wrenches may be incapable of securely gripping the oil filter as required.
Accordingly, there has been a need for a novel oil filter wrench which can adjustably accommodate many different sizes of oil filters and the like, and securely grip an oil filter, without slipping, while torque is being applied through the wrench to the filter. Further, the novel oil filter wrench must be sturdy, capable of being used effectively in the limited space provided within many engine compartments, and built to twist the filter in either a clockwise or counter clockwise direction notwithstanding the positioning of the wrench upon the filter. Finally, there exists a significant need for an easily manufactured and economical oil filter wrench which can be advantageously used by the professional mechanic as well as the home repairman to safely and reliably tighten or loosen oil filters in a variety of situations and applications. The present invention fulfills these needs and provides other related advantages.